Stay-bolt structure.



J. R. FLANNERY, B. E. D. STAFFORD & E. I. DODDS.

STAY BOLT STRUCTURE.

APPLICATION FILED OCT. 25. 19:7.

Patent-ed July 9, 1918.

INVENTORS FV/TNESSES A lzorneys JOHN ROGERS FLANNERY, BENJAMIN E. D. STAFFORD, AND ETHAN I. DODDS, OF PITTS- BURGH, PENNSYLVANIA, ASSIGNORS T0 FLANNERY BOLT COMPANY, OF PITTS- BURGH, PENNSYLVANIA.

Specification of Letters Patent.

STAY-BOLT" STRUCTURE.

PatentedJuly 9, 1918.

To all whom it may concern Be it known that we, JOHN R. FLANNERY, BENJAMIN E. D. STAFFORD, and ETHAN I. DoDns, citizens of the United States, and residents of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Stay-Bolt Structures; and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to improvements in staybolt structures and more particularly in means for denoting the condition of staybolts for boilers,the object of the invention being to provide simple and efficient means whereby the ruptured condition of a staybolt shall be indicated by Visual signal located exteriorly of the staybolt structure.

WVith this and other objects in view the invention consists in certain novel features of construction and combinations of parts as hereinafter set forth and pointed out in the claims.

In the accompanying drawings, Figure 1 is a sectional view showing the application of our improvements when the bolt is in normal condition, and Fig. 2 is a similar view showing the position of the parts when the bolt has been ruptured or broken.

1 represents the inner sheet of a boiler and 2 a staybolt passing through the same and having a tell-tale bore or hole 3.

Within the inner end of the bore 3, a tube or container 4 is inserted,said tube or container being provided at its inner end with a hole 5 and closed at its outer end by means of a plug 6 of suitable non-metal material, such as fireproof porcelain or clay that will harden when burned, for example. The plug 6 is made with a central opening through which a pin 7 is passed and said pin is provided at its outer end with a head 8 normally seated in a recess in the outer end of said plug. A coiled spring 9 is inserted within the tube or container 4: and bears at one end against the inner end of the latter. A block 10 of more or less compressed electrically non-conducting soluble material, such for example as salt, is disposed between the coiled spring 9 and inner end of the pin 7.

The tube or container 4 is in electrical contact with the wall of the tell-tale bore 3 and one terminal of an electric circuit 11 is connected with the boiler sheet (or with the staybolt if desired) and the other terminal of said circuit is connected with the pin 7,- said circuit containing a battery 12 and a lamp or other signaling device 13, and this circuit is maintained open under normal conditions by the disposition of the block 10 of salt between the spring 9 and the pin 7.

Should the staybolt become ruptured so as to admitsteam or water Within the bore 3, such steam or water will pass through the hole 5 in the tube or container 4: and act upon the block 10 so as to dissolve the same and permit the spring to make electrical contact with the pin 7 and thus close the circuit 11 and cause the lamp or other signal 13 to be displayed and thus denote the ruptured condition of the staybolt.

Having fully described our invention what we claim as new and desire to secure by Letters-Patent, is:

1. The combination with a stay bolt having a bore, of a container within said bore, a pin entering said container, a spring located within the container, a block of nonconducting soluble material between the spring and pin, and an electric circuit including said pin and spring and a signal device.

2. The combination with a staybolt having a bore, of a pin, a spring located within said bore, and an abutment for said spring, a block of non-conducting soluble material normally separating said spring and pin, and an electric circuit including the spring and pin and a signal.

3. The combination with a stay bolt having a bore, of a container located within said bore and having openings at both ends, a specification in the presence of two subscribplug closing the bore, a pin passing through ing Witnesses.

said plug, a coiled spring located Within the JOHN ROGERS FLANNERY. container, a block of non-conducting soluble BENJAMIN E. D. STAFFORD. material disposed between said cciled spring ETHAN I. DODDS. and pin andan electric circuit incliidi-fig'the WVithesses coiled spring and pin and a visual H. ALLISON,

In testimony whereof, We have signed this EDWIN S. RYcE.

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